network notifications throwing keyerror if associate a floatingip to a server

steps to reproduce:

1. create a floatingip
2. use "nova floating-ip-associate" to associate the floatingip to a server

A keyerror will be thrown , the traceback in ceilometer-agent-notification.log:

2014-05-31 15:19:43.501 18053 INFO ceilometer.network.notifications [-] network notification {'_context_roles': [u'_member_', u'admin', u'heat_stack_owner'], '_context_request_id': u'req-bd5ed336-242f-4705-836e-8e8f3d0d1ced', '_context_read_deleted': u'no', 'event_type': u'floatingip.update.start', '_context_user_name': u'admin', '_context_project_name': u'admin', 'timestamp': u'2014-05-31 07:19:43.463101', '_context_tenant_id': u'9fc714821a3747c8bc4e3a9bfbe82732', '_context_tenant_name': u'admin', '_context_tenant': u'9fc714821a3747c8bc4e3a9bfbe82732', 'message_id': u'0ab6d71f-ba0a-4501-86fe-6cc20521ef5a', 'priority': 'info', '_context_is_admin': True, '_context_project_id': u'9fc714821a3747c8bc4e3a9bfbe82732', '_context_timestamp': u'2014-05-31 07:19:43.460767', '_context_user': u'6ca7b13b33e4425cae0b85e2cf93d9a1', '_context_user_id': u'6ca7b13b33e4425cae0b85e2cf93d9a1', 'publisher_id': u'network.devstack', 'payload': {u'id': u'64262b2a-8f5d-4ade-9405-0cbdd03c1555', u'floatingip': {u'port_id': u'8ab815c8-03cc-4b45-a673-79bdd0c258f2'}}}
2014-05-31 15:19:43.502 18053 ERROR oslo.messaging.notify.dispatcher [-] Exception during message handling
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher Traceback (most recent call last):
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/notify/dispatcher.py", line 85, in _dispatch_and_handle_error
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher return self._dispatch(incoming.ctxt, incoming.message)
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/notify/dispatcher.py", line 121, in _dispatch
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher metadata)
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher File "/opt/stack/ceilometer/ceilometer/plugin.py", line 107, in info
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher self.to_samples_and_publish(context.get_admin_context(), notification)
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher File "/opt/stack/ceilometer/ceilometer/plugin.py", line 125, in to_samples_and_publish
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher p(list(self.process_notification(notification)))
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher File "/opt/stack/ceilometer/ceilometer/network/notifications.py", line 93, in process_notification
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher resource_id=message['payload']['id'],
2014-05-31 15:19:43.502 18053 TRACE oslo.messaging.notify.dispatcher KeyError: 'id'